<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<title>Title</title>
	</head>
	<body>
		<ul>
			<li>1</li>
			<li>2</li>
			<li>3</li>
			<li id="four">4</li>
			<li>5</li>
			<li class="green yellow">6</li>
			<li class="green">7</li>
			<li>8</li>
			<li>9</li>
			<li>10</li>
		</ul>
		
		<div class="green">111</div>
		<div class="green">111</div>
		<div class="green">111</div>
		<div class="green">111</div>
		<script src="jquery-1.12.4.js" type="text/javascript" charset="utf-8"></script>
		<script type="text/javascript">
			//入口函数
			$(function(){
				//jquery如何设置样式
				//css(name,value)
				//name:样式表  value: 样式值
				
				//id选择器   $("#id")
				$("#four").css("backgroundColor","red");
				
				
				$(".green").css("backgroundColor","green");
				
				$("li").css("color","red");
				
				//交集  并集
				
				$("#four,.green").css("background","pink");
				$("li.green").css("backgroundColor","red");
				$(".green.yellow").css("backgroundColor","hotpink");
				
				
				
			});
		</script>
	</body>
</html>